System and method of detecting strobe using temporal window

ABSTRACT

A video processing device is provided that includes a buffer, a luminance component, a maximum threshold component, a minimum threshold component and a flagging component. The buffer can store frame image data for a plurality of video frames. The luminance component can generate a first luminance value corresponding to a first frame image data and can generate a second luminance value corresponding to a second frame image data. The maximum threshold component can generate a maximum indicator signal when the difference between the second luminance value and the first luminance value is greater than a maximum threshold. The minimum threshold component can generate a minimum indicator signal when the difference between the second luminance value and the first luminance value is less than a minimum threshold. The flagging component can generate a flagged signal based on the maximum indicator signal and the minimum indicator signal.

RELATED CASES

The present application claims priority from U.S. ProvisionalApplication No. 61/799,839, filed Mar. 15, 2015, and from U.S.Provisional Applications No. 61/803,315, filed Mar. 19, 2013, the entiredisclosures of which are incorporated herein by reference.

BACKGROUND

The present disclosure relates to a system for and method of detecting astrobe in an image frame of a video.

BRIEF SUMMARY OF THE DRAWINGS

The accompanying drawings, which are incorporated in and form a part ofthe specification, illustrate example embodiments and, together with thedescription, serve to explain the principles thereof. In the drawings:

FIG. 1 illustrates an example conventional video system;

FIG. 2 illustrates a plurality of frames and a luminance graphcorresponding to a plurality of strobe bursts;

FIG. 3 illustrates a plurality of frames and a luminance graphcorresponding to a long strobe;

FIG. 4 illustrates a plurality of frames and a sliding window;

FIG. 5 illustrates a luminance graph having a luminance peak;

FIG. 6 illustrates another example video system;

FIG. 7 illustrates an example encoder from the video system of FIG. 6;

FIG. 8 illustrates an example method of operating the encoder of FIG. 7;

FIG. 9 illustrates example luminance functions and comparativefunctions;

FIG. 10 illustrates two example image frames as divided into a pluralityof sections;

FIG. 11 illustrates another example video system;

FIG. 12 illustrates example components of the encoder of FIG. 11; and

FIGS. 13A-B illustrate an image frame as divided into a plurality ofsections.

DETAILED DESCRIPTION

The present disclosure is generally drawn to systems and methods ofdetecting a strobe within an image. Strobes are commonly produced invideo. As a cinematic feature, it is often used to signal emotions or asa separator for the transition from one shot to another. Sometimes,strobes are due to physical reasons, such as the video source directlyfacing a directional light source. They strobe typically includes anextremely bright core, surrounded by a transition strip in which thestrength of the brightness gradually degrades away from the core andeventually blends into the background.

Detecting and identifying a strobe within an image frame may be usefulfor many reasons. For example, image frames having strobes therein mayneed different encoding. Therefore, if a strobe can be recognized,appropriate encoding resources may be allocated. For purposes ofdiscussion therein, identification of a strobe within an image will bediscussed in conjunction with encoding. However, it should be noted thatsuch discussion is merely for purposes of explanation, and is not to belimited.

FIG. 1 illustrates a conventional video system 100. As shown in figure,conventional video system 100 includes a video source 102, an encoder104 and a storage/transmission component 106. Non limiting examples ofvideo source 102 include a media server, a camera, a video storage, areceiver and a video decoder (in the context of transcoding, where inputvideo is first decoded and re-encoded into different size, format, etc).

Video source 102 is operable to provide image data 108 to encoder 104.Encoder 104 is operable to provide encoded data 110 tostorage/transmission component 106.

In operation, video source 102 generates image data 108 as a series ofstill images, wherein each still image is called a frame. Each frame iscomposed of a plurality of pixels, wherein each pixel includes pixeldata. Pixel data for each pixel includes at least one characteristic andan associated value of the characteristic(s) of that pixel. Non-limitingexamples of characteristics include chrominance, luminance, etc.Luminance describes the amount of light that is emitted from a pixel.The associated value of the characteristic may be a detected value in apredetermined range. For example pixel data may include as acharacteristic, the amount of detected red in the pixel, whereas theassociated value is on a scale from 0 to 255, wherein zero is anindication that no red has been detected and 255 is an indication that amaximum amount of red has been detected. Similarly, in another example,pixel data include as a characteristic, the amount of detected luminancein the pixel, whereas the associated value is on a scale of 0 to 255,wherein zero is an indication of no detected luminance and 255 is anindication of maximum luminance.

It may be useful to be able to identify a strobe within a frame. Asmentioned earlier for example, for purposes of encoding, additionalencoding resources may be needed to encode a frame having a strobe. Inparticular, some encoding techniques rely on comparisons of adjacentframes to reduce the amount of data needed to describe a frame. In suchencoding techniques, when there are large differences between adjacentframes, more data is required to encode such adjacent frames.

Encoder 104 encodes image data 108. The amount of resources needed toencode image data depends largely on the amount and type of data to beencoded.

To increase the quality of an image, multiple characteristics may beused for pixel data. To further increase the quality of an image, largerscales may be used in association with each characteristic. Stillfurther, to increase the quality of an image, the number of pixels perframe may be increased. As the number of pixels increases, as the numberof characteristics per pixel increases, and as the scale of eachcharacteristic increases, the corresponding amount of data per imageframe increases.

FIG. 2 illustrates a plurality of frames and a luminance graphcorresponding to a Type 1 strobe—a strobe burst. As shown in the figure,frames 202, 204 and 206 depict multiple frames of a singer in which astrobe is flashing in the background for a short burst, for example, 3frames. Luminance graph 208 includes x-axis 212 of image frames, y-axis210 of luminance value and a luminance function 214. One of theplurality of peaks in graph section 216 corresponds to the luminance offrames 202-206.

Luminance graph 208 can indicate the type of strobe being utilized. Forexample, within graph section 216, luminance function 214 fluctuatesrapidly between a high luminance value and a low luminance value. A highluminance value indicates the presence of a bright light, whereas a lowluminance value indicates the presence of a dim light, or no light atall. Therefore, in this example, as the luminance fluctuates rapidlybetween bright light and dim/no light, the assumption is made that thecause of these fluctuations is a strobe burst, pulsing light in a rapidmanner.

Outside of graph section 216 luminance function 214 does not show thesame characteristic fluctuation of a pulsing strobe, so the assumptionis made that there is no strobe burst outside of graph section 216,

FIG. 3 illustrates a plurality of frames and a luminance graphcorresponding to a Type 2 strobe—a long strobe. As shown in the figure,frame set 302 comprises a plurality of individual frames of a singer. Inthis example, the total number of frames is 40, however any number offrames could be used. Luminance graph 304 includes x-axis 308 of imageframes, y-axis 306 of luminance value and luminance function 310. Graphsection 312 corresponds to the luminance of frame set 302.

Luminance graph 306 can indicate the type of strobe present in theplurality of frames. For example, within graph section 312, luminancefunction 310 remains relatively constant at a high luminance value. Ahigh luminance value indicates the presence of a bright light, whereas alow luminance value indicates the presence of a dim light, or no lightat all. Therefore, in this example, as the luminance remains relativelyconstant at a high luminance value, the assumption is made that thecause of the high luminance value is a constant source of bright light,as shown in frame set 302.

A frame having a large luminance value does not necessarily mean thatthe frame includes a strobe. However, a frame having a large luminancevalue is indicative of a potential strobe, either a Type 1 strobediscussed above with reference to FIG. 2, or the Type 2 strobe discussedabove with reference to FIG. 3. In some embodiments disclosed herein, aframe having potential strobe may be verified as a frame having a strobeby analyzing the frame in light of neighboring frames. This will bedescribed with reference to FIG. 4.

FIG. 4 illustrates a plurality of frames and a sliding window.

As shown in the figure, a plurality of frames 400 includes a number offrames, an example of which is indicated by frame 404, inside a framewindow 402. In attempting to determine the presence of a strobe,relative luminance values are important, thus luminance values ofsequential frames may be compared to determine if a strobe is present.For example, in a relatively dim restaurant, if someone were takingpictures with a flash, the flash may be considered a strobe since itwould be a very bright light in comparison to the dim restaurant.However, if the same pictures were being taken in bright daylight, theflash may not be considered a strobe since it would not be a very brightlight in comparison to the light from the sun.

Therefore, when processing a video, in order to determine if a strobe ispresent, the luminance value of a single frame may be compared to theluminance values of the adjacent frames. In FIG. 4, to determine whetherframe 404 contains a strobe, the luminance value of frame 404 may becompared to the luminance values of the remaining frames within framewindow 402. Additionally, frame window 402 is a sliding window,continuously moving as the target frame changes. An example embodimentof luminance values of the frames within frame window 402 will now bedescribed with additional reference to FIG. 5.

FIG. 5 illustrates a luminance graph 500 having a luminance peak. Asshown in the figure, luminance graph 500 includes an x-axis 504 of imageframes and a y-axis 502 of luminance value. A luminance function 506corresponds to a stream of image frames. A peak is noted by 508, and isthe luminance value of frame 404. This means that frame 404 has themaximum luminance value compared to that of other frames in the buffer.Item 510 corresponds to the luminance value of the beginning frame ofthe ramp up to peak 508, indicated by dotted line 516. Item 512corresponds to the luminance value of the end frame of the ramp downfrom peak 508, indicated by dotted line 514.

Peak 508 indicated that frame 404 may potentially have a strobe therein.Further, the luminance value of frame 404 has to be larger than apredetermined threshold to be the peak of potential Type 1 strobeframes. To verify whether peak 508 indicated that frame 404 indeedincludes a strobe, a group of frames may be analyzed. In this case, noframes on either side of frame 404 have a higher luminance than frame404, indicating that frame 404 is exhibiting the highest luminance atpeak 508, which is indicative of a burst strobe.

In adjusting the slopes of ramp estimates 514 and 516, the number offrames included in the strobe frames will change. The general shape ofthe peak is known when ramp up 510 and ramp down 512 have beenidentified, in that the luminance slope becomes flat at those points.Once peak 508 and peak ramp estimates 514 and 516 have been identified,the strobe frames corresponding the identified peak 508 is determined tobe from frame 510 to frame 512.

In some cases, once peak 508 is identified, right side ramp estimate 514may not provide useful feedback. This may indicate that the strobeencountered is not a burst strobe, but a long strobe, in which case themethod for identifying the long strobe is discussed with reference toFIGS. 6-10.

FIG. 6 illustrates another example video system 600. As shown in thefigure, system 600 includes video source 102, an encoder 602 andstorage/transmission component 106. Encoder receives image data 108 andoutputs encoded data 604.

FIG. 7 illustrates an example encoder 602 from the video system 600 ofFIG. 6. As shown in FIG. 7, encoder 602 includes a controller 702, abuffer 704, a luminance component 706, a maximum threshold component708, a minimum threshold component 710, a flagging component 712, averification component 713 and an encoding component 714.

Controller 702 is operable to control buffer 704, luminance component706, maximum threshold component 708, minimum threshold component 710,flagging component 712, verification component 713 and encodingcomponent 714, via control signals 716, 718, 720, 722, 724, 725 and 726,respectively.

Buffer 704 is operable to store frame image data for a plurality ofvideo frames. Luminance component 706 is operable to generate a firstluminance value corresponding to a first image data from the bufferedframe image data and to generate a second luminance value correspondingto a second frame image data from the buffered frame image data. Maximumthreshold component 708 is operable to generate a maximum indicatorsignal when the difference between the second luminance value and thefirst luminance value is greater than a maximum threshold. Minimumthreshold component 710 is operable to generate a minimum indicatorsignal when the difference between the second luminance value and thefirst luminance value is less than a minimum threshold. Flaggingcomponent 712 is operable to generate a flagged signal based on themaximum indicator signal and the minimum indicator signal. Verificationcomponent 713 is operable to generate verification signals indicating averified strobe based on flagged signals from flagging component 712 andluminance value from luminance component 706. Encoding component 714operable to encode at least one of the first frame image data and thesecond frame image data in a first manner or in a second manner based onthe flagging signal and the verification signals.

FIG. 8 illustrates an example method 800 of operating the encoder ofFIG. 7. Method 800 will be described with additional reference to FIG.9.

Method 800 starts (S802) and the system is initialized (S804). Forexample, controller 702 may initialize a counter value, C, correspondingto the number of potential strobe frames, as 0. The value of C is alsoused by the flagging component 712 to generate flagged signals. C>0means strobe is flagged, i.e., the frames being analyzed are flagged ascontaining a potential strobe; C=0 means strobe is not flagged, i.e. theframes being analyzed are flagged as not containing a potential strobe.Resetting C to 0 means to remove the flagged condition.

A series of frames i through i+j are then buffered (S806). The number offrames may be any number suitable for the application. In oneembodiment, the number of frames may be 40. Buffer 704 receives imagedata 108. A frame i+C is then loaded (S808). Frame i+C may be locatedanywhere within frames i to i+j. In one embodiment, frame i+C is locatedhalfway between frame i and frame i+j. The luminance value Y_(i+c) isthen determined (S810). Buffer 704 passes the image data correspondingto the current frame, i+C, to luminance component 706 via signal 728.Luminance component 706 analyzes the luminance values of all the pixelsin the current frame and takes their average to determine the luminancevalue Y_(i+c).

Another frame i+C+k is then loaded (S812). Buffer 704 receives frameimage data for a subsequent frame from image data 108. The subsequentframe may be a frame subsequent by a value k. For example in oneembodiment, when k=1, the subsequent frame is the next frame after thecurrent frame. In this example embodiment, let k=2.

The luminance value Y_(i+c+k) is then determined (S814). Buffer 704passes the image date corresponding to the frame, i+C+k, to luminancecomponent 706 via signal 728. Luminance component 706 analyzes theluminance values of all the pixels in the frame i+C+k to determine theluminance value Y_(i+c+k).

The luminance value differential D is then determined (S816). Luminancecomponent 706 finds the luminance value differential D as the differencebetween the luminance value Y_(i+c) and the luminance value Y_(i+c+k).The differential D can be calculated either by forward differential orby backward differential. Since i, c and k are all positive indexes,forward differential is defined as D=Y_(i+c)−Y_(i+c+k), and backwarddifferential is defined as D=Y_(i+c+k)−Y_(i+c). In the exampleembodiment, a backward differential is used.

It is then determined whether the luminance value differential D isgreater than a predetermined first threshold T₁ (S818). Luminancecomponent 706 provides the luminance value differential D to maximumthreshold component 708 via signal 730 and to minimum thresholdcomponent 710 via signal 732. Maximum threshold component compares D toa predetermined threshold T₁, minimum threshold component compares D toa predetermined threshold T₂.

FIG. 9 illustrates example luminance functions and comparativefunctions. In the figure, a first graph 902 has a y-axis 904 ofluminance value and an x-axis 906 of frame number. Graph 902additionally shows a luminance function 908 of a stream of frames. Alsoin the figure is a graph 910, having a y-axis 912 of a luminance valuedifferential and an x-axis 914 of frame number. Graph 910 additionallyincludes a luminance differential function 916. A first threshold valueT₁ is indicated as dotted line 918 on graph 910, whereas a secondthreshold value T₂ is indicated as dotted line 920 on graph 910.

The luminance value of a frame is compared with the luminance value of aprevious frame. This difference corresponds to luminance differentialfunction 916. In the example of FIG. 9, a current frame is compared to asecond previous frame (not the immediately preceding frame). In otherembodiments, any number of frames may be disposed between the currentframe and the compared frame.

The comparison should highlight large differences in luminance betweennearby frames. This may be used to locate a long strobe. For example,spike 922 is larger than the first threshold. This indicates that thecorresponding frame in graph 902 has a luminance value that is muchlarger than the luminance value of its second previous frame. Spike 926in graph 910 is lower than the second threshold. This indicates that thecorresponding frame in graph 902 has a luminance value that is muchlower than the luminance value of its second previous frame. Inaddition, the luminance value for a strobe frame shall be larger than apredetermined threshold T_(a).

In general, to identify a long strobe, first the differential luminancebetween a frame i and a frame i-k is determined, where i is the currentframe and k is an integer. Then it is determined whether thisdifferential luminance is greater than a predetermined threshold. Inthis example, the first predetermined threshold is T₁ indicated by line918. If it is greater, then the start of a strobe is indicated. Then theframes are continually analyzed until the differential luminance is lessthan a second predetermined threshold. In this example the secondpredetermined threshold is T₂ indicated by line 920. In this exampletherefore, a strobe is indicated at 924 from spike 922 to spike 926. Thecorresponding luminance value as shown in portion 928 of luminancefunction 908 of graph 902 clearly shows a high value.

With additional reference to FIG. 8, an example of D>T₁ (Y at S818), maybe at spike 922 of FIG. 9. If D>T₁ (Y at S818), then the frame isflagged as potential strobe frame by incrementing the counter C so thatit is greater than 0 (S820). The procedure then continues with the nextframe i+C (S808).

If D is not greater than T₁ (N at S818), it is then determined whetherthe luminance value differential D is less than a predetermined secondthreshold T₂ (S822). Minimum threshold component 710 compares D to apredetermined threshold T₂. If D is not less than T₂ (N at S822), thecounter value C is then compared with a predetermined threshold T_(m)(S824). If C is greater than T_(m) (Y at S824), it means the length of apotential strobe frames is larger than a predetermined threshold and thesearch for further strobe frames is forced to stop. The strobe counter Cis then reset to 0 (S826), which also means unflag strobe.

If it is determined that potential strobe frames ended (by previousactions discussed above), all potential strobe frames (in total C ofthem) will be verified (S828). If all the potential strobe frames areverified (Y at S828), then, encoding component 714 is instructed toencode the frames in a first manner which is optimal for strobe frames(S830). Frame i is then incremented by C frames (S832) and the processbegins again with another set of frames (S806).

If the potential strobe frames are not verified (N at S828), thenencoding component 714 is instructed to encode the frames in a secondmanner which is optimal for non-strobe frames (S834). Frame i is thenincremented by C frames (S832) and the process begins again with anotherset of frames (S806).

Regarding the operation of the verification component: the luminancecomponent 706 provides the luminance value Y to the verificationcomponent 713 by signal 750. Also, the flagging component 712 providesthe flagging signal to the verification component 713 by signal 742.

If it is determined that the current series of potential strobe framesended, then they are verified (S828). If the absolute value of all ofthe D values for all the potential strobe frames, as calculated from theluminance values, are added together and averaged, the result is theoverall average differential luminance. If the average differentialluminance is larger than a predetermined threshold T₃, it may indicatethe presence of a strobe. In another embodiment, in addition to theaverage differential luminance test against T₃, the sum of luminancevalues Y for each potential strobe frame is divided by the total numberof potential strobe frames, C, and the result is the average luminancevalue. The average luminance value is tested against a predeterminedthreshold T₄. A potential strobe frame is verified only if its averageluminance value is larger than T₄. In yet another embodiment, themaximum and minimum luminance value for all potential strobe frames aretested against predetermined threshold T₅ and T₆ respectively. Thecurrent series of potential strobe frames may be verified to be strobeframes only if the maximum luminance value is less than T₅ and theminimum luminance value is greater than T₆.

Returning to FIG. 8, if D<T₂ (Y at S822), it is determined whether astrobe has been flagged, i.e., C>0 (S836) in flagging component 714. Anexample of D<T₂ and the strobe being flagged (Y at S836), may be atspike 926 of FIG. 9. If flagged as a strobe by C>0 (Y at S836) then thestrobe is unflagged by resetting C=0 (S826). The potential strobe framesare then verified as strobe/non-strobe (S828) as previously described,and the frame may be encoded as a strobe (S830) or non-strobe (S834).For example, returning to FIG. 9, if the strobe was flagged (C>0) andD>T₁, as seen for example at spike 922 (corresponding to S818), then thestrobe will stay flagged until D<T₂, or until C>T_(m) (S824). In thisexample, it happens at spike 926. As such, the long strobe lasts for allframes between spike 922 and spike 926. This is seen as portion 928 ofgraph 902 and section 924 of graph 910.

Returning to FIG. 8, if not flagged as a strobe, i.e., C is not greaterthan 0 (N at S836), then the frame is encoded as a non-strobe (S838).For example, returning to FIG. 9, if the strobe was not flagged andD<T₂, as seen for example at spike 932, then the frame is not consideredas having a strobe.

Frame i is then incremented by 1 frame (S840) and the process beginsagain a with another set of frames (S806).

If C<T_(m) (N at S824), then the frame is a potential strobe frame, andit is determined whether C>0 (S842) For example, returning to FIG. 9, ifthe strobe was flagged and D is not less than T₂, as seen for example atspike 930, then there is still a potential strobe. Until the bottomthreshold is surpassed the strobe continues. In the example of FIG. 9,strobe 924 continues past spike 930 to spike 926.

If C is not greater than T_(m), and if strobe is not flagged (N atS842), then the frame is encoded as a non-strobe (S838).

The buffer index i is then incremented to the next frame (S840) andmethod 800 continues. If, however, strobe is flagged (Y at S842), thecounter C is incremented (meaning strobe is still flagged), andprocessing continues (S808).

The above discussion with reference to FIGS. 6-9 describes embodimentswhere a strobe is identified by analyzing an entire frame. However, inaccordance with other embodiments, a strobe may be identified byanalyzing portions of a frame. Other embodiments includes a system thatreceives a frame, partitions the frame into m regions where regions mayoverlap each other, calculates and buffers luminance value (Y) for eachregion at a dedicated temporal buffer for that region. A peak (forType 1) may then be detected within a buffer for each region. If a peakis detected, the ramp up and ramp down in the buffer are used to markregions where peak strobes are detected. A difference between luminancevalues of frames are used for Type 2 strobe detection. Type 2 strobeexistence is then verified by checking luminance fluctuation during thestrobe period. If detected and verified, a Type 2 strobe is indicatedfor the frames.

FIG. 10 illustrates image frame 202 as divided into a plurality ofsections 1002 and image frame 204 as divided into a plurality ofsections 1004.

FIG. 11 illustrates another example video system 1100. As shown in thefigure, video system 1100 includes video source 102, an encoder 1102 andstorage/transmission component 106. Video source 102 to is operable toprovide image data 108 to encoder 1102. Encoder 1102 is operable toprovide encoded data 1104 to storage/transmission component 106. Videosystem 1100 is similar to video system 600 of FIG. 6, but differs in thesense that encoder 1102 will process an image frame by processing theplurality of sections.

FIG. 12 illustrates example components of encoder 1102. As shown in thefigure, encoder 1102 includes controlling component 702, an imagedividing component 1202, buffer 704, luminance component 706, maximumthreshold component 708, minimum threshold component 710, flaggingcomponent 712, verification component 713 and encoding component 714.

Controlling component 702 is operable to control image dividingcomponent 1202, buffer 704, luminance component 706, maximum thresholdcomponent 708, minimum threshold component 710, flagging component 712,verification component 713 and encoding component 714, via controlsignals 1204, 716, 718, 720, 722, 724, 725 and 726, respectively.

Image dividing component 1202 is configured to receive image data 108and control signal 1204. Image dividing component 1202 is operable togenerate sections of image data based on image data 108 and output thesections of image data 1206.

Buffer 704 is operable to store sectional frame image data for aplurality of video frames. Luminance component 706 is operable togenerate a first luminance value corresponding to a first sectionalimage data from the buffered sectional frame image data and to generatea second luminance value corresponding to a second sectional frame imagedata from the buffered sectional frame image data. Maximum thresholdcomponent 708 is operable to generate a maximum indicator signal whenthe difference between the second luminance value and the firstluminance value is greater than a maximum threshold. Minimum thresholdcomponent 710 is operable to generate a minimum indicator signal whenthe difference between the second luminance value and the firstluminance value is less than a minimum threshold. Flagging component 712is operable to generate a flagged signal based on the maximum indicatorsignal and the minimum indicator signal. Verification component 713 isoperable to generate verification signals indicating a verified strobebased on flagged signals from flagging component 712 and luminance valuefrom luminance component 706. Encoding component 714 is operable toencode at least one of the first sectional frame image data and thesecond sectional frame image data in a first manner or in a secondmanner based on the flagging signal and the verification signals.

Encoder 1102 is similar to encoder 602 of FIG. 7, but differs in thesense that encoder 1102 includes image dividing component 1202 andcontrolling component 702 is additionally able to control image dividingcomponent 1202.

In the embodiment discussed above with reference to FIG. 10, theindividual sections of image data are analyzed. In other embodiments,sections may be analyzed in an overlapped manner. This is shown in FIGS.13A-B. Without knowing where the strobe pixels are located, overlappedsection partitions may enhance the chance that a section contains amajority of the strobe pixels, hence making the detection more robust.

FIGS. 13A-B illustrate image frame 200 as divided into a plurality ofsections 1302. In FIG. 13A, sections 1304, 1306 and 1308 are groupedtogether as section 1312 for analysis. Alternatively, in FIG. 13A,sections 1306, 1308 and 1310 can be grouped together as section 1314 foranalysis. It is clear that sections 1312 and 1314 overlap with eachother. In FIG. 13B, sections 1306, 1308 and 1310 are grouped together assection 1314 for analysis.

The foregoing description of various preferred embodiments has beenpresented for purposes of illustration and description. It is notintended to be exhaustive or to limit embodiments to the precise formsdisclosed, and obviously many modifications and variations are possiblein light of the above teaching. The example embodiments, as describedabove, were chosen and described in order to best explain the principlesof embodiments and their practical application to thereby enable othersskilled in the art to best utilize embodiments and with variousmodifications as are suited to the particular use contemplated. It isintended that the scope of embodiments be defined by the claims appendedhereto.

We claim:
 1. A video processing device comprising: a buffer operable tostore frame image data for a plurality of video frames; a luminancecomponent operable to generate a first luminance value corresponding toa first image data from the buffered frame image data, and to generate asecond luminance value corresponding to a second frame image data fromthe buffered frame image data; a maximum threshold component operable togenerate a maximum indicator signal when the difference between thesecond luminance value and the first luminance value is greater than amaximum threshold; a minimum threshold component operable to generate aminimum indicator signal when the difference between the secondluminance value and the first luminance value is less than a minimumthreshold; and a flagging component operable to generate a flaggedsignal based on one of the maximum indicator signal and the minimumindicator signal.
 2. The video processing device of claim 1, wherein theflagging component is operable to generate the flagged signal as a firstflagged signal indicating a potential strobe based on the maximumindicator signal.
 3. The video processing device of claim 1, wherein theflagging component is operable to generate the flagged signal as asecond flagged signal indicating no potential strobe based on theminimum indicator signal.
 4. The video processing device of claim 1,further comprising a verification component operable to receive aplurality of flagged signals, and to generate a verification signalindicating a verified strobe, based on the received flagged signals. 5.The video processing device of claim 4, wherein said verificationcomponent is further operable to calculate a count value based on thenumber of received flagged signals, and wherein said verificationcomponent is further operable to generate the verification signaladditionally based on the count value as compared to a predeterminedcount threshold.
 6. The video processing device of claim 4, wherein saidverification component is further operable to receive a plurality of thefirst luminance value and the second luminance value, and wherein saidverification component is further operable to generate the verificationsignal additionally based on the first luminance value and the secondluminance value.
 7. The video processing device of claim 6, wherein saidverification component is further operable to calculate an averageluminance value based on the first luminance value and the secondluminance value, and wherein said verification component is furtheroperable to generate the verification signal additionally based on theaverage luminance value.
 8. The video processing device of claim 6,wherein said verification component is further operable to calculate aminimum luminance value based on the first luminance value and thesecond luminance value, and wherein said verification component isfurther operable to generate the verification signal additionally basedon the minimum luminance value.
 9. The video processing device of claim6, wherein said verification component is further operable to calculatean average difference value based on the first luminance value and thesecond luminance value, and wherein said verification component isfurther operable to generate the verification signal additionally basedon the average difference value.
 10. The video processing device ofclaim 1, further comprising: an image dividing component operable todivide the frame image data for each of the plurality of video framesinto respective sections of image data, wherein said luminance componentis operable to generate the first luminance value corresponding to afirst section of the first image data from the buffered frame imagedata, and to generate a second luminance value corresponding to a secondsection of the second frame image data from the buffered frame imagedata.
 11. A video processing method comprising: storing, via a buffer,frame image data for a plurality of video frames; generating, via aluminance component, a first luminance value corresponding to a firstimage data from the buffered frame image data; generating, via theluminance component, a second luminance value corresponding to a secondframe image data from the buffered frame image data; generating, via amaximum threshold component, a maximum indicator signal when thedifference between the second luminance value and the first luminancevalue is greater than a maximum threshold; generating, via a minimumthreshold component, a minimum indicator signal when the differencebetween the second luminance value and the first luminance value is lessthan a minimum threshold; and generating, via a flagging component, aflagged signal based on one of the maximum indicator signal and theminimum indicator signal.
 12. The video processing method of claim 11,wherein said generating a flagged signal comprises generating theflagged signal as a first flagged signal indicating a potential strobebased on the maximum indicator signal.
 13. The video processing methodof claim 11, wherein said generating a flagged signal comprisesgenerating the flagged signal as a second flagged signal indicating nopotential strobe based on the minimum indicator signal.
 14. The videoprocessing method of claim 11, further comprising: receiving, via averification component, a plurality of flagged signals; and generating,via the verification component, a verification signal indicating averified strobe, based on the received flagged signals.
 15. The videoprocessing method of claim 14, further comprising: calculating, via theverification component, a count value based on the number of receivedflagged signals, wherein said generating a verification signal comprisesgenerating the verification signal additionally based on the count valueas compared to a predetermined count threshold.
 16. The video processingmethod of claim 14, further comprising: receiving, via the verificationcomponent, the first luminance value and the second luminance value, andwherein said generating a verification signal comprises generating theverification signal additionally based on the first luminance value andthe second luminance value.
 17. The video processing method of claim 16,further comprising: calculating, via the verification component, anaverage luminance value based on the first luminance value and thesecond luminance value, wherein said generating a verification signalcomprises generating the verification signal additionally based on theaverage luminance value.
 18. The video processing method of claim 16,further comprising: calculating, via the verification component, aminimum luminance value based on the first luminance value and thesecond luminance value, wherein said generating a verification signalcomprises generating the verification signal additionally based on theminimum luminance value.
 19. The video processing method of claim 16,further comprising: calculating, via the verification component, anaverage difference value based on the first luminance value and thesecond luminance value, wherein said generating a verification signalcomprises generating the verification signal additionally based on theaverage difference value.
 20. The video processing method of claim 11,further comprising: dividing, via an image dividing component, the frameimage data for each of the plurality of video frames into respectivesections of image data, wherein said generating a first luminance valuecomprises generating the first luminance value corresponding to a firstsection of the first frame image data from the buffered frame imagedata, and wherein said generating a second luminance value comprisesgenerating the second luminance value corresponding to a second sectionof the second frame image data from the buffered frame image data.